Hypodermic syringe



April 1970 R. LANGE, JR 0 3,506,006

' HYPODERMIC SYRINGE Filed March 21, 1968 l 2 Sheets-Sheet 1 INVENTOR.Richard Lange, Jr. BY

AGENT April 14, 1970 R. LANGE, JR 3,506,006

HYPODERMIC SYRINGE Filed March 21', 1968 2 Sheets-Sheet z Fig. 4

INVENTOR.

Richard Lange, Jr. BY

AGENT United States Patent O 3,506,006 HYPODERMIC SYRINGE Richard Lange,Jr., Harriman, N.Y., assignor to Corning Glass Works, Corning, N.Y., acorporation of New York Filed Mar. 21, 1968, Ser. No. 714,956 Int. Cl.A61m 5/24 US. Cl. 128220 6 Claims ABSTRACT OF THE DISCLOSURE BACKGROUNDOF THE INVENTION This invention relates to improvements in hypodermicsyringe units and relates particularly to hypodermic syringes that areadapted to be furnished as prefilled sterile units.

Hypodermic syringes require sterilization of the barrel, plunger andneedle prior to use since these components, which come in contact withthe injectable fluid and patient to be injected, must be free ofcontamination. By conventional methods there is a need for humanhandling to load the syringe with the resultant possibility ofcontamination.

In order to obviate the necessity for sterilizing the components of thesyringe and to do away with the necessity of filling the syringe in openair, various prefilled, sealed, sterile hypodermic syringe units havebeen devised. However, in those devised to date, rubber or plasticclosures or pistons are in contact with the fluid from the time that thesyringe is manufactured to the time that it is used. This can result inpoor shelf life since the fluid may attack the rubber closure causing aflaking of the rubber which contaminates the fluid. The fluid may alsohave solvent properties which can leach some of the elements from therubber or plastic pistons and thereby alter the chemical composition ofthe injectable fluid itself. Further, previous prefilled sterilehypodermic syringe units have required very careful assembly proceduressince the filling is done in conjunction with the fabrication of theunit, a very costly and arduous practice.

It is therefore an object of the present invention to provide a sterile,prefilled syringe, in which the fluid does not come in contact withrubber, plastic or metal until the syringe is about to be used.

It is a further object of this invention to provide a sterile prefilledsyringe which is simple and economical to fabricate and assemble.

Another object of this invention is the provision of a sterile,prefilled hypodermic syringe in which the hypodermic needle ismaintained in a sterilized condition until use.

Another object of this invention is the provision of a sterile prefilledsyringe wherein the fluid, until immediately prior to use, is stored inan ampoule.

Another object of this invention is to provide a sterile, prefilledsyringe in which a final filtering of the fluid is made just prior toinjection.

Other objects of the invention will become apparent from the followingdescription of a preferred embodiment of the invention.

SUMMARY OF THE INVENTION Hypodermic syringe units embodying the presentinvention provide for the insertion of an ampoule into the upper end ofthe plunger of the syringe, means for breaking the ampoule upondepression into the plunger, means for forcing the fluid into the barrelof the syringe, means for filtering the fluid as it is forced from theplunger into the barrel of the syringe and means for preventing the flowof the fluid from the barrel back into the plunger once the desiredamount of fluid has been transferred.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a sectional view of apreferred embodiment of the present invention before use.

FIGURE 2 is a sectional view of the preferred embodiment of theinvention after depression of the ampoule into the plunger.

FIGURE 3 is a sectional view of the preferred embodiment of theinvention after depression of the plunger into the barrel of thesyringe.

FIGURE 4 is a sectional view of the preferred embodiment of theinvention after partial Withdrawal of the plunger from the barrel.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGURE 1, thepreferred embodiment comprises a syringe 10, having a barrel 11, aneedle 12 and a plunger 13. Barrel 11 is a generally cylindrical tubularlength of glass or plastic or any of the conventional materials of whichsyringe barrels are formed. The upper end 14 of barrel 11 is open andhas a flange 15. The other end 16 of barrel 11 is closed except for hole17 in which needle 12 is anchored in the conventional manner. Theoutside of end 16 of barrel 1]. has threads 18 upon which is threaded,in an airtight fashion, needle protector 19. Needle protector 19 is agenerally cylindrical body being closed at its lower end and threadedinternally at its upper end, and, as is shown in the drawings, acts as acover for needle 12. The connection between needle protector 19 andbarrel 11 by means of threads 18 is airtight not only to avoidcontamination of the needle before use of the syringe but also to enablefilling of the syringe as hereinafter described.

Plunger 13 is a generally cylindrical glass body, one end being shapedin the form of a flange 20. Aroundthe other end is attached a rubber orplastic piston 21 in the form of a cylindrical sleeve extending aroundthe bottom and sides of projection 22. The connection between piston 21and plunger 13 is made by means of a cylindrical projection 22 having anannular depression 23. Annular internal ridge 25 on piston 21 interlockswith depression 23.

In assembly, piston 21 is forced into plunger 13 so that ridge 25 fitsinto depression 23 holding them together. The fit of piston 21 onplunger 13 is purposely made loose so that the frictional torque betweenprojection 22 and the inner surface of the piston is less than thefrictional torque between piston 21 and the interior wall of barrel 11.This is important for the operation of the syringe as will be more fullyexplained later. Piston 21 is positioned inside barrel 11 in the usualmanner so as to allow the piston to be pushed down or up barrel 11 in anairtight fashion. Hole 26 in piston 21 is located off center of thecenterline of piston 21, insuring that the centerline of piston 21 isnever encompassed by hole 26.

Inside projection 22, in cooperative relationship with hole 26, is hole27. As assembled, holes 26 and 27 are in line with each other. The otherend of plunger 13 has a cylindrical cavity 28 having a truncatingprojection 29 at the end near projection 22. Between cavity 28 and hole27 is located a filter 30. In cavity 28 is positioned, globe first, anampoule 31 prefilled in the usual fashion with the liquid to beinjected, Globe 34 of ampoule 31 has a circumferential score line 36located between tip 35 and the bulb of globe 34. Sealing ring 32 holdsampoule 31 in place and provides an airtight fit of ampoule 31 inplunger 13. A rubber or plastic cover 33 covers the exposed end of theampoule to insure protection against contamination before use.

In operation, the syringe is first heid in a vertical position, plungerend up and needle end down. In this position, the syringe is as shown inFIGURE 1. Plunger 13 is then held firmly from the outside and ampoule 31is driven into the lunger by pressing on cover 33 untii frangible tip 35of ampoule 31 is driven against truncating projection 29, snapping it atscore line 36. The syringe is then as is shown in FIGURE 2.

Next, plunger 13 is driven all the way into barrel 11, as shown inFIGURE 3. Since no air or gas can escape out through needle protector 19because of its airtight connection with threads 18 of barrel 11 betweenthe walls of plunger 13 and barrel 11, the air or gas previously fillingthe cavity in barrel 11 and needle protector 19 is compressed forcing itto pass through hole 26, hole 27, filter 30 and into ampoule 31. At thistime, the pressure in both barrel 11 and plunger 13 has been increasedbeyond the pressure present therein prior to use. Next, plunger 13 isslowly pulled up barrel 11 away from hole 17. In so doing, the vacuumcreated in barrel 11 and the additional pressure in plunger 13 causes apressure differential to exist across filter 30, forcing the fluid to bedriven through filter 30 into the growing cavity in barrel 11. This iscontinued until more than the required dosage of the fluid hasaccumulated in barrel 11.

At this point, plunger 13 is rotated 180 with respect to barrel 11.Since the frictional torque between projection 22 and piston 21 is lessthan the frictional torque between piston 21 and barrel 11, plungerprojection 22 will rotate inside piston 21 without any rotation ofpiston 21. After this is accomplished, holes 26 and 27 are no longeraligned and there is no communication between them. The upper end ofhole 26 now abuts the solid end of projection 22 and the lower end ofhole 27 now abuts the solid wall of piston 21. The condition of thesyringe is now as is shown in FIGURE 4. At this point, the syringe isnot uniike any conventional syringe. After needle protector 19 has beenremoved, the syringe is then expirated until all the air or gas isdriven from that portion of barrel 11 between piston 21 and needle 12and from the needle, until the exact dosage remains. It is then readyfor use and is thereafter used as is any ordinary syringe.

It should be noted that the provision of filter 30 provides for a finalfiltering of the fluid just prior to injection. Along with any glassparticles resulting from breaking of ampoule 31, any solids which mayhave been included in the fluid in assembly of the ampoule are filteredout.

Ampoule 31 may initially be sealed with a positive internal pressuregreater than that of the syringe interior, thereby facilitating the flowof liquid from the ampoule to the syringe when the ampoule tip isbroken. Similarly, the interiors of the plunger and barrel may bemaintained at a negative pressure to facilitate flow from the ampoule.

Further, the invention provides for the use of an ampoule and eliminatesthe need for costly assembly to insure uncontaminated filling ofsyringes as in present prefilled syringes. Also, while the syringe is instorage prior to use, there is no contact between the liquid and anyrubber or plastic pistons or sealing rings. The liquid during thisperiod of time is in contact only with the glass of ampoule 31.Consequently, the possibility of contamination of the fluid by reactionwith the rubber or plastic or by flaking of the rubber or plastic iseliminated. Contact between the fluid and the rubber or plastic is ofvery short duration regardless of shelf life and so the shelf life of asyringe embodying the invention is limited only by the shelf life of theampoule.

Inasmuch as the foregoing description has been provided solely as thatof the preferred embodiment of the invention, the scope of the presentinvention is to be limited only by the scope of the appended claims.

What is claimed is:

1. A hypodermic syringe comprising a hollow barrel,

a hypodermic needle communicating with the interior of said barrel at afirst end thereof,

a hollow plunger reciprocable within said barrel through a second endthereof,

a fluid container within said plunger,

means for opening said fluid container to permit flow of fluid from saidcontainer to said plunger,

means for reciprocating said plunger in said barrel,

means forming a channel between said plunger and said barrel for theflow of fluid therebetween,

means for opening and closing said channel, and

removable closing means for closing said needle to prevent fluid flowtherethrough,

whereby fluid is able to pass between said plunger and said barrel whensaid channel is open and said plunger is operable to expel fluid throughsaid needle when said channel is closed and said closing means isremoved from said needle.

2. A hypodermic syringe according to claim 1 in which said fluidcontainer is an ampoule reciprocable within said plunger and having afrangible tip extending generally in the direction of said needle, and

said means for removing said frangible portion is a projection on theinner wall of said plunger in the vicinity of said frangible tip and ata location to exert pressure on said frangible tip as said ampoule ismoved in the direction of the end of said plunger within said barrel,and

which includes means for moving said ampoule in the direction of the endof said plunger within said barrel.

3. A hypodermic syringe according to claim 1 which includes filter meansbetween said fluid container and said barrel in a position to filterfluid passing therebetween.

4. A hypodermic syringe according to claim 1 in which said means foropening and closing a channel between said plunger and said barrelcomprises a piston at the end of said plunger within said barrel androtatable with respect to said plunger,

a first fluid channel passing through said plunger at its end withinsaid barrel, said fluid channel being olfset from the centerline of saidpiston,

a second fluid channel passing through said piston, said second fluidchannel being offset from the centerline of said piston by substantiallythe same distance as that by which said first channel is offset, and

means for elfecting relative rotation between said piston and saidplunger,

5. A hypodermic syringe according to claim 4 in which said piston is inthe form of a sleeve having cylindrical inner and outer surfaces andextending around the side and end of a cylindrical projection extendingfrom the end of said plunger, and

said sleeve is in engagement with the inner surface of said barrel, suchthat relative rotation between said plunger and said sleeve can beelfected by rotation of said plunger to effect or interruptcommunication through said channels between the interiors of said barreland the interior of the plunger.

6. A hypodermic syringe comprising a hoilow barrel having a cylindricalinner surface,

a hypodermic needle communicating with the interior of said barrel at afirst end thereof,

a hollow plunger having a cylindrical outer surface and beingreciprocable within said barrel through a second end of said barrel,

at least a portion of said inner surface of said plunger beingcylindrical,

an ampoule within said plunger having at least a portion of its outersurface in the form of a cylinder complementary to the cylindrical innersurface of said plunger and having a frangible tip extending toward theend of said plunger nearer said needle,

an inwardly projecting portion on the inner surface of said plungeradapted to break off said frangible tip on said ampoule when saidampoule is moved in the direction of said needle,

a cylindrical projection on said plunger concentric with the cylindricalsurfaces of said plunger and extending in the direction of said firstend of said barrel,

a sleeve extending around the side and end of said projection on saidplunger, said sleeve having a cylindrical inner surface complementary tothe outer surface of said projection and a cylindrical outer surfacecomplementary to the cylindrical inner surface of said barrel,

said sleeve being in frictional engagement with said projection and saidbarrel, the frictional force between said sleeve and said barrel beinggreater than 2 the frictional force between said sleeve and saidprojection, whereby rotation of said plunger effects relative rotationbetween said plunger and said sleeve,

said plunger having a fluid-flow channel extending through saidprojection and communicating with the interior of said plunger,

said sleeve having a fluid-flow channel extending therethrough,

said fluid-flow channels being offset from the centerline of saidcylindrical surface of said projection by equal amounts such thatrelative rotation between said plunger and said sleeve can bring saidchannels into and out of communication with one another, and

filter means located between said frangible tip of said ampoule and saidhypodermic needle for filtering fluid passing therebetween.

References Cited UNITED STATES PATENTS 2,841,145 7/1958 Epps 128--2183,076,456 2/1963 Hunt 128--218 3,348,546 10/1967 Roberts et al. 128218RICHARD A. GAUDET, Primary Examiner G. F. DUNNE, Assistant Examiner US.Cl. X.R.

